Condensation of Indoline with Some 1,2-and 1,3-Diketones

Bismuth nitrate catalyzed condensation reactions of indoline with 1,2- and 1,3-diketones were investigated and were reported to proceed via different reaction pathways with the involvement of one or two of the carbonyl groups. While the reaction of indoline with cyclohexane-1,3-dione (4) gave solely condensation product, the reaction between the acetylacetone (5) and indoline provided N-acetyl indoline as single products on retro-aldol process. In contrast to 1,3-diketones, the reaction with benzil (17) was performed under difficult conditions and proceeded to give secondary products.